Generally used to describe a video card capable of running two displays. Also used to describe a computer set up with two displays connected

This page has been created primarily to link to some notes on how to acheive the latter of these two definitions

There are basically two ways to acheive a dual head setup, you need either a DualHead video card (a video card that supports 2 displays), or use two cards to run the two displays (ie one display each).

The X11 protocol has long had support for multiple cards. For the XOrg server, this is done by configuring multiple "Device" and "Screen" sections in the xorg.conf file.

For DualHead cards the setup is somewhat specific to the brand of card you have. For XOrg you can use its Xinerama extension, but some cards/drivers use their own method for dual head.

For an example of dual-head using Xinerama, (with the Intel i810/i915 graphics chipset + driver), see i915-xorg.conf.

Nvidia based cards use their own method - see TwinView.

For Ati/radeon based cards see DualHeadAti.